This disclosure relates to protective metallic coatings on structural components.
Metallic coatings are often used to protect airfoils from environmental conditions, such as to resist oxidation. The metallic coatings may also serve as a bond coat for adhering topcoat layers of ceramic coatings or other barrier materials. Metallic coatings are normally not used for structural components formed from superalloys, such as disks that are used to mount blades. Disks may be exposed to higher stresses than airfoils, while still operating in aggressive environmental conditions (e.g. oxidation and hot corrosion). As such, disk alloys are made of different superalloy materials than airfoils to enhance environmental durability without debiting disk mechanical performance (e.g., fatigue). Application of traditional environmental coatings to disks can severely debit the disk fatigue capability.